CBS drama vet “NCIS: Los Angeles” is taking advantage of the three-network comedy collision on Tuesday, dominating the half-hours on ABC, NBC and Fox in key demos this week. NBC’s “The Voice” remained the night’s top show among young adults.

According to preliminary national estimates from Nielsen, “NCIS: Los Angeles” averaged a 2.8 rating/7 share in adults 18-49 and 15.7 million viewers overall in the 9 o’clock hour — on par with its most recent outing and comfortably ahead of the timeslot’s comedy blocks on other nets. It beat its closest competition, NBC’s comedies, by 40% in adults 18-49 (2.0/5) and by 60% in adults 25-54 (4.0/9 vs. 2.5/6).

Also on the night for CBS, “NCIS” was on the low side (3.0/9 in 18-49, 16.9 million viewers overall), but was the night’s top scripted program in 18-49, 25-54 (4.6/11) and total viewers. And at 10 p.m., rookie drama “Vegas” (1.6/4 in 18-49, 10.4 million viewers overall) was second among the broadcasters in 18-49 and first in 25-54 (2.3/6) and total viewers.

The Eye finished a close second to NBC in 18-49 on the night while winning in adults 25-54 and more than doubling the total-viewer delivery of any other net.

At NBC, “The Voice” (3.8/11 in 18-49, 11.0 million viewers overall) won the leadoff hour in 18-49 and was a close second to “NCIS” in 25-54 (4.5/11). It was followed by first-year comedies “Go On” (2.3/6 in 18-49, 6.3 million viewers overall), which was off slightly from its most recent original, and “The New Normal” (1.8/5 in 18-49, 4.7 million viewers overall), which was up slightly. And at 10, “Parenthood” continues to have a quietly solid fall (1.8/5 in 18-49, 4.7 million viewers overall), winning among the Big Three in 18-49.

Fox’s “Raising Hope” (1.6/5 in 18-49, 3.8 million viewers overall) was in line with its recent performances, but 8:30 p.m. newcomer “Ben & Kate” is struggling (1.1/3 in 18-49, 2.5 million viewers overall). From 9 to 10 p.m., the net’s comedies “New Girl” (2.2/6 in 18-49, 4.3 million viewers overall) and “The Mindy Project” (1.7/4 in 18-49, 3.2 million viewers overall) closely trailed their NBC comedy competition. “Mindy” was up 13% in 18-49 from its most recent original and posted its top women 18-34 score (3.0/8) since its premiere.

ABC is really struggling on the night, and midseason changes are expected. Following the “Dancing With the Stars” results show (third-place 1.9/5 in 18-49, 11.9 million viewers overall), the net ranked a distant fourth among the Big Four from 9 to 10 p.m. with “Happy Endings” (1.4/4 in 18-49, 4.8 million viewers overall) and “Don’t Trust the B in Apt. 23” (1.1/3 in 18-49, 3.2 million viewers overall), both of which were at season-low levels. And capping the night was a weak showing by “Private Practice” (1.1/3 in 18-49, 3.7 million viewers overall), which was also at its lowest level to date.

CW’s “Hart of Dixie” (0.7/2 in 18-49, 1.7 million viewers overall) hit season highs, drawing its largest overall audience since last December. And that seemed to boost rookie “Emily Owens, M.D.” (0.4/1 in 18-49, 1.4 million viewers overall), which was up across the board.

Preliminary 18-49 averages for the night: NBC, 2.6/7; CBS, 2.5/7; Fox, 1.7/4; Univision, 1.6/4; ABC, 1.4/4; CW, 0.5/1.

In total viewers: CBS, 14.3 million; NBC, 7.1 million; ABC, 6.5 million; Univision, 4.0 million; Fox, 3.5 million; CW, 1.6 million.